Conventional semi-automatic pistols can be accidently fired under extraordinary circumstances when the firing pin is forcefully displaced either by the hammer or its own inertia. For example, it might be possible to fire a semi-automatic pistol in the cocked condition by forcibly striking the pistol on its hammer or its muzzle. The prior art has addressed the aforementioned problem and examples of firing pin locking devices are disclosed in U.S. Pat. Nos. 2,846,925; 3,724,113; 3,830,002; and 4,021,955 and British Pat. Specification No. 660,046. However, the devices shown in the aforementioned patents are not suitable for incorporation into the most popular semi-automatic pistols which are similar in design to the Colt 1911 and 1911A1models.
In addition, conventional semi-automatic pistols incorporate a hammer having a half-cocked notch with a lip which can engage the tip of the sear although such a possibility is extremely unlikely. If an engagement of this nature occurs, the hammer could possibly fall from the half-cocked position and discharge the firearm.